Audience
Web developers interested in a suite of developer tools for Firefox
About Firefox Developer Tools
Firefox Developer Tools is a set of web developer tools built into Firefox. You can use them to examine, edit, and debug HTML, CSS, and JavaScript. This section contains detailed guides to all of the tools as well as information on how to debug Firefox for Android, how to extend DevTools, and how to debug the browser as a whole. You can open the Firefox Developer Tools from the menu by selecting Tools > Web Developer > Web Developer Tools or use the keyboard shortcut Ctrl + Shift + I or F12 on Windows and Linux, or Cmd + Opt + I on macOS.
Other Popular Alternatives & Related Software
FoxyProxy
FoxyProxy is an advanced browser extension for Chrome, Firefox, and other Chromium-based browsers that replaces and vastly extends native proxy settings by letting users create, manage, and switch among multiple proxy server profiles with fine-grained control; it supports automatic switching based on URL patterns (wildcards or regular expressions), individual browser tabs, Firefox containers, or private windows, as well as manual selection via colored icons. Users can define inclusion/exclusion rules, test patterns with a built-in tester, toggle WebRTC to limit IP leakage, and import/export full configurations or just rules for backup or sharing, with optional synchronization across instances via browser sync. The interface includes keyboard shortcuts, visible color/country flag cues per proxy, advanced logging for debugging, which proxy was used when, and quick-add flows to capture new rules.
Learn more
Chrome DevTools
Chrome DevTools is a set of web developer tools built directly into the Google Chrome browser. DevTools can help you edit pages on-the-fly and diagnose problems quickly, which ultimately helps you build better websites, faster. There are many ways to open DevTools, because different users want quick access to different parts of the DevTools UI. When you want to work with the DOM or CSS, right-click an element on the page and select Inspect to jump into the Elements panel. Or press Command+Option+C (Mac) or Control+Shift+C (Windows, Linux, Chrome OS). When you want to see logged messages or run JavaScript, press Command+Option+J (Mac) or Control+Shift+J (Windows, Linux, Chrome OS) to jump straight into the Console panel. Toggle various overlays and speed up DOM tree navigation with badges. The main uses of the Chrome DevTools Console are logging messages and running JavaScript.
Learn more
Firefox Developer Edition
Welcome to your new favorite browser. Get the latest features, fast performance, and the development tools you need to build for the open web. All the latest developer tools in beta, plus experimental features like the multi-line console editor and WebSocket inspector. A separate profile and path so you can easily run it alongside release or beta Firefox. Preferences tailored for web developers, browser and remote debugging are enabled by default, as are the dark theme and developer toolbar button. Firefox DevTools now grays out CSS declarations that don’t have an effect on the page. When you hover over the info icon, you’ll see a useful message about why the CSS is not being applied, including a hint about how to fix the problem. The new Firefox DevTools are powerful, flexible, and best of all, hackable. This includes a best-in-class JavaScript debugger, which can target multiple browsers and is built in React and Redux.
Learn more
weinre
weinre is WEb INspector REmote. Pronounced like the word "winery". Or maybe like the word "weiner". weinre is a debugger for web pages, like FireBug (for Firefox) and web inspector (for WebKit-based browsers), except it's designed to work remotely, and in particular, to allow you to debug web pages on a mobile device such as a phone. weinre was built in an age when there were no remote debuggers available for mobile devices. Since then, some platforms are starting to provide remote debugger capabilities, as part of their platform toolset. weinre reuses the user interface code from the web inspector project at WebKit, so if you've used Safari's web inspector or Chrome's Developer Tools, weinre will be very familiar. In normal usage, you will be running the client application in a browser on your desktop/laptop, and running a target web page on your mobile device. weinre does not make use of any 'native' code in the browser, it's all plain old boring JavaScript.
Learn more
Pricing
Starting Price:
Free
Free Version:
Free Version available.
Integrations
Company Information
Mozilla
Founded: 1999
United States
developer.mozilla.org/en-US/docs/Tools
Videos and Screen Captures
Other Useful Business Software
Forever Free Full-Stack Observability | Grafana Cloud
Built on open standards like Prometheus and OpenTelemetry, Grafana Cloud includes Kubernetes Monitoring, Application Observability, Incident Response, plus the AI-powered Grafana Assistant. Get started with our generous free tier today.
Product Details
Platforms Supported
Cloud
Windows
Mac
Linux
Training
Documentation
